Greets!
No need to lighten it unless you just want to, Dave just adds it to all his drawings since some are sold as flat packs, so want to make it as light as practical to cut shipping costs.
No illustration other than the info on the cab drawing. AFAIK. you're the first to ask for more details as it's self explanatory.
WRT the amp, if it works with your little cab, then it means you may need to add some series resistance to fine tune a larger cab.
If you decide to build a 90 L cab, then the tall cab goes away since it won't be big enough to mount the driver, so you'll need stands if you want them at seated ear height, losing the floor's boundary gain down in the bass. Of course you can skip the stands and slant the baffle to aim it up at you, though some folks find this a bit odd sounding if there's much tilt, so recommend keeping it to < 12 deg if you go this route.
GM
No need to lighten it unless you just want to, Dave just adds it to all his drawings since some are sold as flat packs, so want to make it as light as practical to cut shipping costs.
No illustration other than the info on the cab drawing. AFAIK. you're the first to ask for more details as it's self explanatory.
WRT the amp, if it works with your little cab, then it means you may need to add some series resistance to fine tune a larger cab.
If you decide to build a 90 L cab, then the tall cab goes away since it won't be big enough to mount the driver, so you'll need stands if you want them at seated ear height, losing the floor's boundary gain down in the bass. Of course you can skip the stands and slant the baffle to aim it up at you, though some folks find this a bit odd sounding if there's much tilt, so recommend keeping it to < 12 deg if you go this route.
GM
Bummer! Now that I'm forced to have 'Odamnbamacare', me and my friends get the same [lack of] quality of care as others socialized healthcare.
Up to ~5x more acoustic power down low is what with 300 L when tuned to Fs. Compare sims in a TL/horn designer program to see how much more LF efficiency it has over a 90 L cab tuned to Fs.
Why does the XO need some serious reworking of the xover if > 1W? I've never heard of such a thing for any driver. If true, the 300 L in a half space sim can handle 10 W down to 30 Hz, so will definitely need it.
WRT your speaker, room acoustics, glad they work fine for you, but Daniel's stated performance goals can't be met with a 90 L cab except possibly corner loaded if his corners yield as much gain as yours do, leaving him no positioning or other tuning options.
WRT your 8 dB cut, at what frequencies and how low do they go flat? A corner only adds a max of 9 dB and most rooms that's been measured/published don't exceed 4-5 dB down below ~40 Hz.
GM
If you increase efficiency in the bass to above what a ported cab delivers the mids will be too low.
For their BLH cabs Tannoy either rework the crossover to pad the bass down or add a front-loaded horn for the mids like in the Westminster or Autograph models to get a flat output.
Since the demise of the Monitor Gold series at the end of the '60s Tannoy drivers are optimised for SS amps. They benefit hugely from lots of power (much more than one would expect looking at the figures) and low output impedance. A series resistor is the very last thing I would contemplate using with Tannoys but then again I wouldn't use a valve amp either as the bass tends to sound 'mushy', uncontrolled and overblown with them.
When I first got my Little Reds (92dB/1W/1m) I used a 50W amp but they only really showed what they can do when I got hold of a 250W amp. I have no idea why that should be.
I run mine 3way active now with a 12" Volt covering the bass so it was quite easy to knock 8dB off below 250Hz, they are now +-2dB from 25-20 000Hz at my listening position.
For their BLH cabs Tannoy either rework the crossover to pad the bass down or add a front-loaded horn for the mids like in the Westminster or Autograph models to get a flat output.
Since the demise of the Monitor Gold series at the end of the '60s Tannoy drivers are optimised for SS amps. They benefit hugely from lots of power (much more than one would expect looking at the figures) and low output impedance. A series resistor is the very last thing I would contemplate using with Tannoys but then again I wouldn't use a valve amp either as the bass tends to sound 'mushy', uncontrolled and overblown with them.
When I first got my Little Reds (92dB/1W/1m) I used a 50W amp but they only really showed what they can do when I got hold of a 250W amp. I have no idea why that should be.
I run mine 3way active now with a 12" Volt covering the bass so it was quite easy to knock 8dB off below 250Hz, they are now +-2dB from 25-20 000Hz at my listening position.
oh so the drawing is the explanation on what i quoted.. cool cool, just my ability of reading english which lacks 😉
about the amp, then I won't add some series resistances or anything like that, nor will I make changes in the XO - possibly some new capacitors, but that's a whole other story!
As it is right now, the 50 ltr cabs are on stands - would be nice to make them something a la floor model, so I wont miss the deepest tones (in some songs it just disappears compared to other speakers I've had)
Really in some kind of dilemma.. luxury problems hehe
Some exciting experience you have with the good old Tannoys!! been using my Tannoys with 4 different amps; a B&K ST-140, a DIY Hiraga (2x 30 w class A), a SET valve construction from a danish firm (Audio Classic), and then what i have now, the 8x EL84 valve construction from the danish firm LA audio '94.. last mentioned is by far the best sounding amp plugged to the Tannoys.. really clean and transparent sound, mids are perfectly balanced and the top frequencies are charmingly spreading in the room, not tending to be metallic as I think the 2" horns to maintain the top can be sometimes.. The bas is not mushy, actually tight - but so tight it isn't there at all in some heavy songs - that's why I think of the bigger cabs. (aint afraid of a little rumble, but afraid of losing the charming mids)
another dilemma!!
In my opinion the best Tannoy speakers by far are those which use extra bass drivers like the FSM, 215DMT, Buckingham Monitor and the legendary Dreadnought.
With that in mind and with no consideration of budget so far I would put the Tannoys in small sealed cabs and add an active woofer below about 200Hz. Turn yours into Buckingham Minis, I like to think of mine as 12" FSMs. ;-)
I may have just added to your dilemmas. Sorry about that!
PS: I don't think your nass is too tight. Your Tannoys as they are are simply missing the bottom octave below 55Hz.
With that in mind and with no consideration of budget so far I would put the Tannoys in small sealed cabs and add an active woofer below about 200Hz. Turn yours into Buckingham Minis, I like to think of mine as 12" FSMs. ;-)
I may have just added to your dilemmas. Sorry about that!
PS: I don't think your nass is too tight. Your Tannoys as they are are simply missing the bottom octave below 55Hz.
All true, but what's your point? This isn't going to be a problem with the MLTL unless driven with a very high output impedance that raises the effective Qts [Qts'] above ~0.403 and even then only if stuck in a corner, but vent damping or worst case, blocking, the vent will solve the problem.
OK, so you're saying that your driver is optimized for low output impedance tube or SS amps rather than the DC2528, which is optimized for high output impedance tube or current drive SS amps?
Obviously, using resistors [and which type] in series with a speaker driver is a personal preference choice, but considering the sheer number of highly rated DIY, consumer, commercial, prosound speakers that employ them either by themselves or as part of a BSC ckt., we need to leave it to the owner to make that choice or use some other form tonal balance control.
'Tube' bass is only 'mushy' if it's a high output impedance, but tube amps in general kept getting 'tighter' over time due to increasing its damping factor [DF] with increasing amounts of negative feedback [-fb] to the point [~1/8 ohm] where it was considerably < the speaker wire's resistance [~0.5 ohm], so even the sum of the two no longer had any audible impact on bass performance as shown using this calculator to find the system Q [Qts']: mh-audio.nl - Home
Yeah, with a sub or at least corner loaded, one doesn't need a large cab, just one tuned low enough to properly either blend to the sub or the corner's gain curve, but otherwise, Frolger does if he wants as much bass down to Fs as the DC2528 is capable of short of a truly huge BLH.
GM
This is true of any wide range driver and especially co-ax, though WRT to separate subs, I recommend doing it Dr. Geddes's way of at least three; one for each set of room modes, width, depth and height and use an 80 Hz XO, which will allow him to continue using his existing cabs.
Better still, extend his existing cabs and load a 'helper' woofer in each to take the 'stress' off the DC.
GM
I'm saying that since the MG all Tannoy drivers have been designed with transistor amps in mind. That includes my 3148s and Frolger's 2528s.
What kind of speaker wire do you use that has around 0.5Ω?
My very standard cable has less than a tenth of that ie 4.5Ω/km which with a 10m round trip to and from the amp gives 0.045Ω.
Not a great fan of subwoofers. I'd turn the Tannoys into large 3ways with a decent but actively driven woofers. Would give Frolger the best of both worlds: A well-controlled SS bass and smooth valve mids and treble.
And again if you increase bass efficiency with a BLH the mids from around 300Hz on up will be too low in level necessitating a reworking of the crossover to pad the bass down again or adding a short front-loaded horn and reduced padding of the tweeter.
Hi guys. Thank you for all the input - really bringing some useful and exciting information in this thread 🙂
The subwoofer/3-ways speaker with active driven woofers ufortunately can't be realized. I got a budget (which is also the reason why i won't buy resistors/pay for having them installed). Since "all" kinds of wood/MDF is relatively free for me, I would like to see how far I can get, only by making new cabs (only paying for minor tweaks as acoustic insulation).
regards, Daniel
The subwoofer/3-ways speaker with active driven woofers ufortunately can't be realized. I got a budget (which is also the reason why i won't buy resistors/pay for having them installed). Since "all" kinds of wood/MDF is relatively free for me, I would like to see how far I can get, only by making new cabs (only paying for minor tweaks as acoustic insulation).
regards, Daniel
So the 300 ltr cab is the only solution, where I won't need to add any thing (to other things than the cab)?; ask if the wording isn't understandable 😀
if that's the case, I will begin make some sketching on the approx. 300 ltr cab that GM recommended!
if that's the case, I will begin make some sketching on the approx. 300 ltr cab that GM recommended!
Yes, if you're not willing to even buy some resistors, but wood, construction labor is cheap enough, then building as much acoustic efficiency as you can afford is your only viable option, so the ultimate would be a Westminster concept compound [front and back loaded] horn.
None has been designed for the DC series AFAIK and seriously doubt it would do well in one as is, leaving only the 300 L MLTL, though as already discussed, it can be reduced in size if they will only be hard against a wall and even more if designed for corners.
GM
None has been designed for the DC series AFAIK and seriously doubt it would do well in one as is, leaving only the 300 L MLTL, though as already discussed, it can be reduced in size if they will only be hard against a wall and even more if designed for corners.
GM
been looking at the front and back loaded horn too.. or just the front-loaded.
"everything" is possible.. thinking of shrinking the volume to an approximately 200 ltr (been thinking about the 300 ltr and 10".. won't look quite fancy, though the 200 ltr solution wont either i guess 😀)
think i will go for the MLTL and build as much acoustic efficiency as possible (within the laws of physics, haha)
"everything" is possible.. thinking of shrinking the volume to an approximately 200 ltr (been thinking about the 300 ltr and 10".. won't look quite fancy, though the 200 ltr solution wont either i guess 😀)
think i will go for the MLTL and build as much acoustic efficiency as possible (within the laws of physics, haha)
FWIW, the 1960 Altec chart I used in my early DIY years that calculates an ideal reflex vent area [Av] = driver effective piston area [Sd], then the cab's net volume [Vb] would be around 927 L + driver, bracing; whereas the ~300 L one I posted based on the measured specs that calculates the largest net Vb is actually 'only' ~290 L net, so feel free to make it up to ~3.2x larger to reach the max practical net Vb for this size driver without fear of going beyond the size limit set by the pioneers of audio where the cab can no longer 'support' the driver at resonance.
Having built cabs up to ~1133 L net, tuned as low as 20 Hz for 15" drivers, they were truly awesome performers at a time when most recordings rolled off below 60-80 Hz, making a T/S spec'd BR cab sound 'thin'/'boomy' in comparison, though had they been 'forced' to reproduce organ or similar they would have 'boomed' quite heavily I'm sure and at high distortion beyond a fraction of a watt, requiring either heavily damping the vent or completely sealing it off to make it an infinite baffle [IB], so of course don't recommend making cabs this large nowadays for a 10" unless they are IB.
GM
Having built cabs up to ~1133 L net, tuned as low as 20 Hz for 15" drivers, they were truly awesome performers at a time when most recordings rolled off below 60-80 Hz, making a T/S spec'd BR cab sound 'thin'/'boomy' in comparison, though had they been 'forced' to reproduce organ or similar they would have 'boomed' quite heavily I'm sure and at high distortion beyond a fraction of a watt, requiring either heavily damping the vent or completely sealing it off to make it an infinite baffle [IB], so of course don't recommend making cabs this large nowadays for a 10" unless they are IB.
GM
Hi ! did you finish your project ? is the xover the original ?
there is a guy here selling a pair of similar Dorset ( i guess with the same DC) for little cash ... i have to check. Maybe they are broken
I love the Tannoy concept ... i have some 8" but i would love to try the 10"
Heard it in the Eaton and i was amazed
What a nice sound
Thanks and regards, gino